Vtable verification currently does not work properly with
link time optimization.  Until this can be fixed users should
not be allowed to specify both options together.

2019-09-04  Caroline Tice  <cmtice@google.com>
 
        *  opts.c (finish_options):  Disallow -fvtable-verify and -flto to be
           specified together.

From-SVN: r275388